水击驻波场中分散相颗粒的运动分析

Analysis of dispersed phase parcitle movement under the action of water-hammer standing wave field

根据水击在管段内形成的驻波场现象,分析了流体内分散相颗粒受到的驻波作用力;运用李雅普诺夫稳定判据研究了颗粒积聚与分离的机理;考虑到颗粒运动方程的严重刚性而很难进行数值求解,采用相空间和非对称分析方法获得了分散相颗粒的运动轨迹近似解,并进行了实验验证。结果表明:水击驻波场中分散相颗粒的受力方程中惯性项对颗粒初始运动速率的影响不可忽略;在水击驻波波节的±λ/4范围内,分散相颗粒经过一定的时间会发生积聚,其运动速度呈对称分布,最大速度出现在3λ/8位置处;随着分散相颗粒粒径和密度等物性参数以及水击驻波的频率和连续相初始速度的增大,颗粒达到平衡位置的时间呈减小趋势,且连续相的初始速度对颗粒到达波节时间的影响显著。

Based upon the water-hammer standing wave field in a pipe,the standing wave acoustic force of the dispersed phase particle in a fluid pipe is analyzed;The mechanism of the particle accumulation and separation from continuous phase based on Lyapunov stability criterion is investigated;The particle motion equations are quite stiff and hence difficult to solve numerically.The phase space and asymmetrical analysis method is adopted,an approximate solution of the dispersed phase particle trajectories is obtained,and experimental verification is also carried out.Results show that the dispersed particles of motion equation of inertia can not be ignored under the action of water-hammer standing wave field,it affects the initial motion velocity rate of the particle;Within the range of ± λ/ 4of water hammer standing wave,particles accumulate after a certain period,and the particle speed distributes symmetrically,the maximum speed appears in the location 3λ /8of the wave;It is obvious that with the increasing of the dispersed phase particle size,density,water hammer wave frequency and continuous phase velocity,the time needed to reach the equilibrium position tends to decrease,and the initial velocity of the continuous phase affects the time of particle arrival wave node significantly.